The whiteness of an unexposed area of a printed image in a light-sensitive material to be directly seen by human eyes, gives an important influence on the quality of the printed image. The increasing in the whiteness of the background of the printed image results increasing in the contrast, in the color purity or chromatics, and in the beautifullness of the picture. Accordingly, various methods for raising the whiteness have been devised. The use of a fluorescent whitening agent has been known as an effective means for raising the whiteness of a printed image obtained from a light-sensitive material. The method for improving the whiteness by the use of the fluorescent whitening agent includes a method by which the fluorescent whitening agent is contained in a processing solution to be used in a color formation processing. Such the method is described in, for example, Japanese Examined Patent Publication (JP) Nos. 46-35240, 49-20975 and 50-25336. However, the above method has such drawbacks that the fluorescent whitening effect is insufficient and the stability of the processing solution is degraded. Recently, the composition of the processing solution used in the processing of the light-sensitive material is further diversified accompanied with the diversification of the processing apparatus and the processing system. Accordingly, a printing light-sensitive material is required, by which a high whiteness can be stably obtained under various processing conditions using a processing solution containing no fluorescent whitening agent.
By another method for using the fluorescent whitening agent, the fluorescent whitening agent is contained in a light-sensitive material. The method is described, for example, in JP Nos. 46-21189, 48-2762, 49-10696, 51-28225 and 52-32254. Although the whiteness of an unexposed area of a print can be raised by this method, the method has a serious drawback such that fogging caused by light of an electrostatic discharge or a static mark is formed in the course of production or processing of the light-sensitive material, for example, at the time of coating constituting layers of the light-sensitive material at a high speed, transporting the light-sensitive material in a color printer, and a tape stuck on the surface of the light-sensitive material is peeled off.
As a means by which the whiteness of a print is raised by adding the fluorescent whitening agent to the light-sensitive material and the above-mentioned static mark can be inhibited, Japanese Patent Publication Open for Public Inspection (JP O.P.I.) Nos. 59-71049 and 59-71050 describe a technique by which a layer containing a compound capable of capturing the fluorescent whitening agent is arranged at a position farther from the support than that of a layer containing the fluorescent whitening agent. However, the static mark preventing effect of such the technique is recently become insufficient because the static mark tend to frequently formed accompanied with a considerable increasing in the transportation speed in the printer for corresponding speedup of the light-sensitive material processing.
Furthermore, speedup of the processing is recently strongly demanded particularly in the field of color paper. Therefore, reduction in the amount of gelatin contained in the light-sensitive material is demanded since it is effective for raising the processing speed by increasing the immersing rate of ingredients of processing solution into the light-sensitive material. However, it has been found that the static mark defect is increased when the gelatin amount in the light-sensitive material is reduced.
For realizing a higher whiteness corresponding to a requirement of higher quality print image, it is effective to increase the amount of the compound capable of capturing the fluorescent whitening agent. However, it is found that, in such the case, the pressure resistivity of the light-sensitive material is lowered and a fog, desensitization and surface defect tend to be formed by applying pressure on the surface of the light-sensitive material in the course of processing or drying. A technology is disclosed in U.S. Pat. No. 4,794,071, JP No. 56-51336 and JP O.P.I. No. 2-168249, by which the fluorescent whitening agent is contained in a support of light-sensitive material. However, such the technique is accompanied with problems that the cost of the support is made higher and the surface uniformity of the support is difficultly maintained. Accordingly, a technology is demanded, by which a high whiteness of the print can be obtained even when a support containing no fluorescent whitening agent is used.